Patent Literature 1 (Japanese Patent No. 4548584) discloses a rebar tying device configured to tie a plurality of rebars by a wire. The rebar tying device in Patent Literature 1 includes a feeder configured to feed the wire wound around a reel by a rotation of a motor, a guide configured to guide the wire fed by the feeder around the plurality of rebars, a cutter configured to cut the wire fed by the feeder at a predetermined position, a twister configured to twist the wire around the plurality of rebars, and a control unit. Moreover, the rebar tying device in Patent Literature 1 includes a detector configured to detect a feeding length of the wire fed by the feeder. The detector includes a plurality of magnets and a Hall element. In this rebar tying device, the control unit controls a feeding length of the wire based on the feeding length of the wire detected by the detector.